Objective: Trichomonas vaginalis is a single-celled protozoan with structures such as flagella and axostyle, and it infects only the humans. This parasite, the causative agent of trichomoniasis, ranks high among sexually transmitted agents all over the world. Although culture methods continue to be used for diagnostic purposes, using cryopreservation methods instead of keeping the microorganism with continuous subcultures helps maintenance of the safe for a long time. In this study, we aimed to determine the effects of using horse serum at various rates on the viability of Trichomonas vaginalis trophozoites during cryopreservation.

Methods: In our study, the isolate of Trichomonas vaginalis encoded as ATCC 30188 was cultivated in TYM media. For cryopreservation, 20%, 50%, 70%, and 90% of horse serum + DMSO were added to a certain amount of medium and 1 ml of the mixture was transferred into sterile cryotubes and frozen. It was thawed at the time of the study and checked for growth in the following days.

Results: It has been observed that increasing rates of horse serum in Trichomonas vaginalis isolates contributes to viability in cryopreservation. The viability of the isolates cryopreserved with 20%, 50%, 70% and 90% of horse serum were found to be 50%, 60%, 70% and 75%, respectively. The isolate continued to grow at similar high rates in the following days, as well.

Conclusion: The use of increasing concentrations of horse serum has a positive effect in the cryopreservation of Trichomonas vaginalis. Unique biological properties of cells and microorganisms should be taken into account while creating cryopreservation protocols, and the most appropriate rates of all biochemical content should be calculated.